News this week of PSD approval for the long awaited chafer grub treatment from Bayer Environmental Science will come as excellent news to green keepers, groundsmen, amenity turf managers and lawncare professionals across the country.
Named Merit Turf®, the product has undergone extensive UK trials over the last four years and was finally given approval by the Pesticide Safety Directorate in February. This makes Merit® Turf the only approved chafer treatment available in the UK.
It will prove a boon to golf courses, bowling greens, athletic fields, commercial and residential lawns and other managed amenity turf situations, where damage from the grub (the larval stage of the chafer beetle family) and foraging birds and animals has been devastating in certain parts of the country.
The product also has approval for the treatment of leatherjackets, providing dual pest control from a single application per year.
Merit® Turf is a granular product supplied in a 10Kg bag within an outer box with measuring cylinder. The product is applied uniformly over the area being treated with normally used granular application equipment. Hand held, drop type and rotary type spreaders can also be used however, with its very low dose rate, the use of spreaders that would apply the granule in narrow, concentrated bands should be avoided.
The active ingredient in Merit® Turf has sufficient residual activity to enable applications to be made prior to the egg laying activities of the target pests, normally from middle of May to middle of June, thus providing optimum levels of control. This period can normally be anticipated when you see the beetle eggs in the soil. One application per year, at the rate of 30kg per hectare, is recommended for chafer grub control with an application made in late spring/early summer.
The activity for Merit® Turf is both curative and preventative.
The active ingredient imidacloprid is in the chloronicotinyl class, which acts by blocking the receptor sites in an insect’s nervous system. Insects that have ingested or absorbed the imidacloprid stop what they are doing or suspend normal behaviour. Basically they stop feeding immediately and do not survive. The grubs will either be affected by eating the turf roots (where the product has been transported systemically) or by absorption through their outer body.
Trials of Merit® Turf showed up to 100% control within 4.5 months, and continued success after 11 months, effectively giving a year’s control from a single application. A 50% improvement in greening effect and a 90% increase in grass vigour were also reported in treated areas.
Since the demise of Gammacol Turf in 1999, chafer grubs have become the amenity turf manager’s nightmare.
The initial damage – yellowing and general weakening of the turf – is caused by the grubs eating the roots of the turf, resulting in a yellowing and a loosening of the turf. Birds and animals such as rooks and badgers then pull the loose turf up to feed on the grub, inflicting secondary damage.
May to July are notoriously bad months for chafer grub activity (when feeding of the 1 and 2 instar larvae takes place) with areas that have high sand content soils being particularly susceptible.
Merit® Turf will be available from the beginning of April 2006 from all Bayer UK distributors.
Bayer Environmental Science www.bayer-escience.co.uk